Acute nerve compression and the compound muscle action potential^[*]

 

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Abstract

Detecting acute nerve compression using neurophysiologic studies is an important part of the practice of clinical intra-operative neurophysiology. The goal of this paper was to study the changes in the compound muscle action potential (CMAP) during acute mechanical compression. This is the type of injury most likely to occur during surgery. Thus, understanding the changes in the CMAP during this type of injury will be useful in the detection and prevention using intra-operative neurophysiologic monitoring.

The model involved compression of the hamster sciatic nerve over a region of 1.3 mm with pressures up to 2000 mmHg for times on the order of 3 minutes. In this model CMAP amplitude dropped to 50% of its baseline value when a pressure of roughly 1000 mmHg is applied while, at the same time, nerve conduction velocities decline by only 5%. The ability to detect statistically significant changes in the CMAP at low force levels using other descriptors of the CMAP including duration, latency variation, etc alone or in conjunction with amplitude and velocity measures was investigated. However, these other parameters did not allow for earlier detection of significant changes.

This study focused on a model in which nerve injury on a short time scale is purely mechanical in origin. It demonstrated that a pure compression injury produced large changes in CMAP amplitude prior to large changes in conduction velocity. On the other hand, ischemic and stretch injuries are associated with larger changes in conduction velocity for a given value of CMAP amplitude reduction.

^*This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

• References

• 1 Moller AR. Intra-Operative Neurophysiologic Monitoring. Humana Press; Totowa NJ: 2005
  Google Scholar
• 2 Happel L, Kline D. Intra-Operative neurophysiology of the peripheral nervous system in Neurophysiology in Neurosurgery: A Modern Intraoperative Approach (Deletis V and Shils J eds). Academic Press; 2002
  Google Scholar
• 3 Gasser HS, Erlanger J. The role of fibre size in the establishment of a nerve block by pressure or cocaine. American Journal of Physiology 1929; 88: 581-591
  PubMedGoogle Scholar
• 4 Ochoa J, Fowler TJ, Gilliatt RW. Anatomical changes in peripheral nerves compressed by a pneumatic tourniquet. J Anat 1972; 113: 433-455 1271414 4197303
  PubMedGoogle Scholar
• 5 Powell HC, Myers RR. Pathology of experimental nerve compression. Lab Invest 1986; 55: 91-100 3724067
  PubMedGoogle Scholar
• 6 Dyck PJ, Lais AC, Giannini C, Engelstad JK. Structural alterations of nerve during cuff compression. Proc Nat Acad Sci 1990; 87: 9828-9832 55267 2263633 10.1073/pnas.87.24.9828
  CrossrefPubMedGoogle Scholar
• 7 Ochoa J, Marotte L. The nature of the nerve lesion caused by chronic entrapment in guinea-pig. J Neurol Sci 1973; 19: 491-495 10.1016/0022-510X(73)90045-2 4724822
  CrossrefPubMedGoogle Scholar
• 8 Omura T, Sano M, Omura K, Hasegawa T, Nagano A. A mild acute compression induces neurapraxia in rat sciatic nerve. International Journal of Neuroscience 2004; 114,12: 1561-1572 10.1080/00207450490509285
  PubMedGoogle Scholar
• 9 Szabo RM, Sharkey NA. Response of peripheral nerve to cyclic compression in a laboratory rat model. J Orthop Res 1993; 11: 828-833 10.1002/jor.1100110608 8283327
  CrossrefPubMedGoogle Scholar
• 10 Rydevik B, Nordborg C. Changes in nerve function and nerve fibre structure induced by acute, graded compression. J Neurol Neurosurg Psychiatry 1980; 43 (12) 1070-82 7217952
  CrossrefPubMedGoogle Scholar
• 11 Causey G, Palmer E. The effects of pressure on nerve conduction and nerve fibre size. Journal of Physiology 1949; 109: 220-231 1392600 15407227
  CrossrefPubMedGoogle Scholar
• 12 Fern R, Harrison PJ. The effects of compression upon conduction in myelinated axons of the isolated frog sciatic nerve. J Physiol 1991; 432: 111-122 1181320 1886055
  CrossrefPubMedGoogle Scholar
• 13 Katz B, Miledi R. The effect of temperature on the synaptic delay at the neuromuscular junction. J Physiol 1965; 181: 656-670 1357674 5880384
  CrossrefPubMedGoogle Scholar
• 14 Battista AF, Alban E. Effect of graded ligature compression on nerve conduction. Exp Neurol 1983; 80: 186-194 10.1016/0014-4886(83)90015-8 6832269
  CrossrefPubMedGoogle Scholar
• 15 Li J, Shi R. Stretch induced nerve conduction deficits in guinea pig ex vivo nerve. J Biomechanics 2007; 40: 569-578 10.1016/j.jbiomech.2006.02.009
  CrossrefPubMedGoogle Scholar
• 16 Fox JL, Kenmore PI. The effect of ischemia on nerve conduction. Exp Neurol 1967; 17: 403-419 10.1016/0014-4886(67)90127-6 6020656
  CrossrefPubMedGoogle Scholar
• 17 Hansson S. The association between nerve conduction velocity and compound motor action potential amplitude during ischemic blocking. Electromyogr Clin Neurophysiol 1999; 39: 113-122 10207681
  PubMedGoogle Scholar
• 18 Yamada T, Muroga T, Kimura J. The effect of tourniquet induced ischemia on somatosensory evoked potentials. Neurology 1981; 31: 1524-1529 7198203
  CrossrefPubMedGoogle Scholar
• 19 Quinones-Hinojosa A, Lyon R, Zada G, Lamborn KR, Gupta N, Parsa AT, McDermott MW, Weinstein PR. Changes in transcranial motor evoked potentials during intramedullary spinal cord tumor resection correlate with postoperative motor function. Neurosurgery 2005; 56: 982-993 10.1227/01.NEU.0000156784.46143.A5 15854246
  PubMedGoogle Scholar
• 20 Zucker RS, Regehr WG. Short term synaptic plasticity. Ann Rev Physiol 2002; 64: 355-405 10.1146/annurev.physiol.64.092501.114547
  CrossrefPubMedGoogle Scholar
• 21 Enoka RM, Rankin LL, Stuart DG, Volz KA. Fatigability of rat hindlimb muscle: associateions between electromyogram and force during a fatigue test. J Physiol 1989; 408: 251-270 1190402 2778729
  CrossrefPubMedGoogle Scholar